The agreement announced Wednesday calls for Pacific Biodiesel to provide between 250,000 gallons and one million gallons of biodiesel to the airport's emergency power facility each year.

Hawaiian Electric will normally use the facility to feed Oahu's power grid. But, if there's a natural disaster, the facility will automatically separate itself from the grid and supply power directly to the airport. Hawaiian Electrics says the facility will use a variety of fuels in this case.

The facility will be able to supply 65 percent of the airport's energy needs.

The $20 million emergency power facility is expected to come online later this year. Construction began last year.